Space Vector Pulse Width Modulation Research Articles

Improved virtual SVPWM algorithm for CMV reduction and NPV oscillation elimination in Three-Level NPC inverter

An improved virtual space vector pulse-width modulation (IVSVPWM) strategy is presented to address simultaneously the problem of common mode voltage (CMV) with neutral point voltage (NPV) fluctuations in wind power converters. The proposed IVSVPWM method suppresses the amplitude of the common mode voltage to Udc/6 by discarding the positive small vector. Meanwhile, the new virtual vector is synthesized by selecting a vector whose neutral point current sums to zero among the retained voltage vectors. In addition, a feedback mechanism is established in the proposed strategy. According to the feedback result, the distribution coefficients of each basic vector in the virtual vector are recalculated to suppress the NPV fluctuation. Through the above control strategy, the dual effect of suppressing the CMV and balancing the NPV is achieved in the full modulation. The feasibility and effectiveness of the strategy are verified by simulation and experiment.© 2017 Elsevier Inc. All rights reserved.

Control of 7-phase permanent magnet synchronous motor drive post three failures

<span lang="EN-US">The article is introducing a new control technique for the 7-phase permanent magnet synchronous motor (PMSM) drive to enhance its robustness against the failure of phases ‘a’ and ‘c’ in addition to the failure of the encoder occurring simultaneously. The article is firstly developing a new multi-dimension space vector pulse width modulation (SVPWM) technique as a part of the fault-tolerant control technique (FTC) to control the magnitudes and angles of the motor’s current after the failures of phases ‘a’ and ‘c’. Moreover, the paper is developing another FTC to obtain a sensorless operation of the 7-phase motor after the failure in the encoder while the phase ‘a’ and ‘c’ are faulted based on the tracking of the saturation saliency. Simulation results prove that the ripple in the speed post the three failures was maintained to be less than 10 rpm compared to 2 rpm when the 7-phase drive is running without faults. In addition to that, the results demonstrated that the motor responded to instant changes in speeds and loads with a dynamic response very close to that obtained when the 7-phase motor ran under healthy operating conditions.</span>

Active Neutral Point Clamped Three-level Synchronous Space Vector Width Modulation Research

Active neutral point clamped (ANPC) topology is widely studied because it makes loss equalization possible. To reduce the switching frequency of high power traction systems, the multi-mode modulation strategy is used in many modulation methods. To reduce the fluctuation problem when switching between different carrier ratios in multi-mode synchronous space vector pulse width (SSVPWM) modulation algorithm, this paper studies the stator flux under different modes and proposes a multi-mode SSVPWM switching strategy based on the pulse insertion method. In this strategy, the stator flux deviation of two modes before and after the switching point is calculated online and the switch sequence is inserted at the switching time to compensate, and the smooth transition between different modes is realized with experimental verification of validity.

Sideband Harmonic Model Considering Sampling Delay Effect in the PMSM Drives With Regular Sampled SVPWM Technique under the Low Carrier Frequency Ratio

Regular sampled space vector pulse-width modulation (SVPWM) is a widely implemented technique in permanent magnet synchronous machine (PMSM) drives with the voltage-source inverter (VSI). The modulation technique would generate the sideband harmonics and increase electromagnetic loss, vibration, and acoustic noise. Therefore, a fast and accurate evaluation of sideband harmonics is particularly important. However, the carrier frequency ratio could be relatively low in some applications, which means it would cause sampling delay and influence the sideband harmonics. This paper analyzes the sampling delay effect in PMSM drives, and proposes a modified sideband harmonic model using Lagrange expansion and complex coordinate transformation for both symmetric and asymmetric regular sampling methods. Furthermore, the amplitudes and phases of whole sideband harmonic components are derived. Experiment results are carried out to validate the accuracy improvement of the modified model, which reveals that it could give a superior estimation of the sideband harmonics in the PMSM drives under the low carrier frequency ratio.

A unified duty-cycle modulation algorithm for a three-level NPC inverter

In this paper, it is a kind of challenge to simplify the conventional pulse width modulation (PWM) algorithms for a three-level neutral-point-clamped inverter. Thus, the unified duty-cycle modulation (UDM) algorithm is presented. It is more attractive than the carrier-based PWM (CBPWM), space-vector PWM (SVPWM), and unified PWM algorithms with a simpler calculation by utilizing the usefulness of the SVPWM algorithm to synthesize the duty cycles in time-domain and the CBPWM algorithm to synthesize the duty cycles in frequency-domain with the lesser conditions and the blankness of the lookup tables, switching sequence design, and zero-sequence component finding. Besides, it is outstanding with three outcomes: (1) comprehensive mathematical models of the dwell times, (2) permanent mathematical models of the duty cycles in time-domain, and (3) simplified PWM algorithm, which has a better workflow with the reduction of the computation burden. As it is very easy to implement as the sinusoidal PWM technique while its performance is equivalent to the SVPWM algorithm, this makes the proposed UDM algorithm a good candidate to optimize between the performance and the cost. Both the simulation and experimental results can confirm the feasible practicability and performance. The comparison with the conventional algorithms can evidently emphasize the superiority.

Segment Reduction-Based Space Vector Pulse Width Modulation for a Three-Phase F-Type Multilevel Inverter with Reduced Harmonics and Switching States

An improved segment reduction-based space vector pulse width modulation (SVPWM) for an F-type three-level inverter (FT2LI) is presented in this article. The proposed SVPWM algorithm decreases the additional switching state transition of each triangle with the application of an improved nine- and three-segment reduction switching strategy. The main feature of the segment reduction technique is that it eliminates second-order harmonics in the inverter output side with good total harmonic distortion (THD), low switching losses, and minimum filter requirements when compared with carrier-based PWM (CBPWM) techniques such as multi-carrier sine PWM (MC-SPWM), sixty-degree PWM (60° PWM), and switching frequency optimal PWM (SFO PWM). The proposed modulation algorithm for FT2LI is implemented on the MATLAB/Simulink platform. The performance of the proposed segment reduction-based SVPWM algorithm is tested experimentally on an FT2LI at various amplitude and frequency modulation indices, and the experimental results are verified with the simulation results. Additionally, a comparative analysis carried out to study the relationship between the segment reduction-based SVPWM and CBPWM techniques inferred that the suggested segment reduction-based SVPWM algorithms can optimize high-order harmonic distributions and have a minimum computational burden.

Comparison of 2L + 2M and 6L SVPWM for Five-Phase Inverter to Reduce Common Mode Voltage

Multiphase drives have received a lot of interest because of their several features over traditional three-phase systems for high-power applications. Pulse-width modulation (PWM) approaches are necessary to regulate the supply for multiphase ac drives. As a result, it is vital to continually improve the modulation and control approaches used to upgrade output power converters’ quality. This paper offers a comparative analysis of the 2L + 2M and 6L space vector pulse-width modulation (SVPWM) techniques applied to a five-phase two-level voltage source inverter (VSI) fed an inductive (R-L) load. The comparative evaluation is based on measuring the inverter switching losses, the total harmonic distortion (THD) values, and the common mode voltage (CMV) under different operation scenarios. A system model is carried out by MATLAB/Simulink. An experimental prototype is constructed in the lab to validate the theoretical analysis. Simulation results for the system based on the two SVPWM techniques are obtained at different modulation indices and different output frequencies and are confirmed by the experimental results. It has been found that the peak-to-peak CMV of the 6L method is 80% lower than that of the 2L + 2M method. Moreover, 6L SVPWM offers better DC-link utilization compared to 2L + 2M SVPWM.

Measurement and analysis of magnetic properties under SVPWM excitation for soft magnetic composites (SMCs) and silicon steel

This study developed a system for measuring the magnetic properties of soft magnetic materials under space vector pulse width modulation (SVPWM) excitation, enabling testing at different modulation indexes, frequencies, and carrier frequencies. Two types of soft magnetic materials were tested, and the effects of SVPWM waveform parameters on material loss were analyzed. The results show that the loss of SMCs is higher than that of silicon steel when the max magnetic flux density is close to 1.5 T. In contrast, at the modulation frequencies are 100 Hz and 200 Hz, the loss of SMCs is lower than that of silicon steel. The reliability of the testing system was validated through magnetic characterization of the two materials, providing a reference for their application and preparation.

Vector Control Technology of Five‐Phase Induction Motor without Speed Sensor Based on Speed‐Adaptive Full‐Order Observer

The five‐phase induction motor, being the most elementary form of multiphase induction motors, boasts low noise, low torque fluctuations, and high load‐bearing capacity, and is hence suitably employed in domains where high power and reliability are required. In light of the susceptibility of the speed encoder to interference from external environments, this paper proposes a sensorless vector control technique for the five‐phase induction motor based on a speed‐adaptive full‐order observer. The proposed approach first employs the nearest four‐vector space vector pulse width modulation (NFV‐SVPWM) as the modulation technique for the five‐phase inverter, in order to provide a constant switching frequency and low harmonic losses. Subsequently, the expression for the speed‐adaptive full‐order observer is constructed based on the mathematical model of the fundamental space of the five‐phase induction motor, and the expression for the adaptive speed law is deduced using the Lyapunov function. Additionally, the bilinear transformation method is utilized as the discretization technique for the full‐order observer during the process of digital implementation, in order to achieve higher discrete accuracy. Finally, an experimental study involving a 4.5 kW five‐phase induction motor was conducted to validate the accuracy and effectiveness of the proposed method. © 2023 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC.

Standby Losses Reduction Method for Flywheels Energy Storage System Based on Hybrid Space Vector Pulse Width Modulation

The flywheel energy storage system (FESS) can operate in three modes: charging, standby, and discharging. The standby mode requires the FESS drive motor to work at high speed under no load and has the longest operating time. Therefore, reducing the standby losses is of great significance for further promoting the application of FESS. In the paper, a novel modulation technique based on hybrid space vector pulse width modulation (HSVPWM) is proposed to reduce the standby losses of the FESS. By the reasonable arrangement of the zero vectors and non-zero vectors, the proposed method can reduce the switching frequency and eliminate the dead time, which reduces the standby losses of the FESS effectively. The modeling, simulation, and analysis verify the effectiveness of this method in reducing the standby loss of the FESS.

Field oriented controlled permanent magnet synchronous motor drive for an electric vehicle

<span lang="EN-US">The paper describes field oriented control strategy with space vector pulse width modulation technique of permanent magnet synchronous motor drive system for an electric vehicle. At first, mathematical models of the motor and the drive system for electric vehicle are presented. In order to obtain high performance drive and maximum motor torque, field oriented control strategy and space vector pulse width modulation technique method are applied to drive system in next section. Speed controller design utilizing the popular zero-pole elimination approach causes large integral constant time in case of small rotational damping constant. The desired-transient-response-based approach is employed to overcome the problem. Performance indices include overshoot, undershoot, steady-state speed error, and total harmonic distortion of stator current, are employed to assess the drive systems with two speed controller design methods. Theoretical assumptions are confirmed via simulations and criteria in MATLAB/Simulink environment.</span>

Experimental analysis of advanced control technique for a five‐phase direct matrix converter based on space vector PWM

AbstractThe multiphase matrix converter outperforms the conventional three‐phase system with higher fault tolerance capability and higher power control competency. This paper discusses the direct control based on different possible switching combinations of a three‐phase to five‐phase matrix converter (MC). The proposed control topology significantly reduces the switching commutations in a switching cycle when compared with its counterpart. The control is based on the modified space vector pulse width modulation (SVPWM) strategy. The proposed space vector scheme intelligently selects the voltage vectors to get the desired output characteristics with the least possible switching transitions in a switching cycle. Three possible cases exist in controlling space vectors based on their magnitude, the number of active switching vectors, and their commutations. The results for three different cases of SVPWM have been presented and compared. The total harmonic distortion (THD) obtained in the output is lower in case 2; however, it suffers from a higher common‐mode voltage (CMV). The scheme has been successfully implemented and verified in hardware.

Rotor Field-Oriented Control of Doubly Fed Induction Generator in Wind Energy Conversion System

In this study, robust and high-performance vector control of a rotor side converter (RSC) was performed for stability and efficient operation doubly fed induction generator (DFIG) based on the variable speed wind turbine (VSWT). The mathematical model of the DFIG is simulated in the computer. Amplitude and frequency of the voltage in the DFIG were controlled for different values of load and variable speeds. In the experimental study, a DFIG-based wind turbine system was set up in the laboratory. The field position of the stator was detected from stator voltages by a phase-locked loop (PLL) circuit. The rotor position was measured with an incremental encoder connected to the rotor shaft of the DFIG. The angular position of the slip was calculated by the difference between the rotor and the stator field positions. The frequency and amplitude of rotor currents were determined with the angular position of slip. To generate output voltages of converter feeding rotor windings, the space vector pulse width modulation (SVPWM) technique was used. In the experimental study, the RSC was controlled with the DS1103 board. The prepared experiment set was tested at different operating speeds.

Hybrid Modulation Strategy for Common-mode Voltage Suppression in Three-level Inverters

A hybrid modulation strategy is proposed to suppress the common-mode voltage (V com) of the three-level PWM inverter on the strength of the SVPWM modulation algorithm (space vector pulse width modulation) for V com generated during the run of the three-level inverter. The three-level space vector is classified as two different modulation areas by modulation ratios. In the low modulation ratio region, according to the nearest three vectors principle, the spatial voltage vector is obtained by combining the small vector with the medium vector, which suppresses V com and ensures that only one bridge arm is switched for any voltage vector. In the high modulation ratio region, the vector with large common-mode voltage is discarded, and the zero-vector, medium-vector, and large-vector are selected to synthesize the space voltage vector, which suppresses V com and ensures the good output current waveform of the PWM inverter. From the simulation results, we can see the hybrid modulation strategy of dividing the region by modulation ratio reduces the magnitude of V com to 1/6 of the dc bus voltage, and at the same time, a good current waveform is obtained at the output of the three-level inverter.

Single-Phase AC-DC-AC Multilevel Five-Leg Converter Based on a High-Frequency Transformer

This paper investigates a single-phase ac-dc-ac multilevel five-leg converter based on a high-frequency transformer. The system consists of a three-leg module with a full-bridge module connected to the shared part of the system. In the proposed configuration, the dc link of the three-leg module is supplied by the full-bridge module through a single active bridge converter. This feature improves the power quality and efficiency of the structure and simplifies the design of the control strategy compared to the conventional solution that uses floating capacitors. The proposed system is composed of a shunt unit and a series unit. The first one is responsible for compensating reactive power and harmonic currents, while the second one provides load voltage compensation against voltage sags and harmonics in the grid voltage. In addition, the proposed converter operates with low dc-link voltages in applications with the same input and output frequency, such as unified power quality conditioner. The model of the system, a space-vector pulse-width modulation and the overall control scheme are addressed. Simulations and experimental results are presented to confirm the feasibility of the proposed converter and the correctness of the design methodology.

EVOLUTION AND DISSEMINATION OF SPECIALIZED STRATEGIES, METHODS, AND TECHNIQUES OF SYNCHRONOUS PULSEWUDTH MODULATION FOR CONTROL OF VOLT-AGE SOURCE INVERTERS AND INVERTER-BASED SYSTEMS

This publication provides a brief historical overview of the development of methods and techniques of pulsewidth modulation (PWM) for voltage source inverters, published mainly in Ukrainian publishing houses and in Ukrainian periodicals. Accent has been done to review of results of investigation of alternative methods and techniques of synchronous space-vector-based multi-zone PWM for inverters with low switching frequency. In particular, in the mentioned publications, the basic strategies, schemes, and algorithms of synchronous multi-zone modulation have been further developed, modernized, modified, and disseminated in relation to new promising topologies of power conversion systems, including: two-inverter-based electric drives with open-end winding of electrical motor; dual three-phase electric drives of symmetrical and asymmetric types; powerful six-phase systems based on four inverters, and two-inverter-based and three-inverter-based photovoltaic installations with multi-winding transformer. It is shown that the developed schemes and algorithms of synchronous space-vector PWM, applied for control of inverter-based systems, provide continuous synchronization and symmetry of basic voltage waveforms of systems during the whole control range including zone of overmodulation of inverters. It provides minimization of even harmonics and undesirable subharmonics (of the fundamental frequency) in spectra of the basic voltages of systems, leading to reducing of losses in systems and to increasing of its efficiency. Based on a comparative analysis of the integral spectral characteristics of the phase and line voltages of systems, recommendations are formulated for the rational choice of schemes and algorithms of synchronous modulation for the relevant installations, depending on the modes of their operation. References 30, tables 2, figures 25.

Modeling and analysis of the LC filter-integrated quasi Z-source indirect matrix converter for the wind energy conversion system

A Quasi Z-Source Indirect Matrix Converter (QZSIMC) is proposed in this paper for Permanent Magnet Generator (PMG) based Direct Drive Wind Energy Conversion Systems (DDWECS) to enhance the voltage transfer ratio and also to control the output voltage under various loading conditions. The QZSIMC comprises three Quasi Z-Source (QZS) networks connected between PMG and load through a three-phase Indirect Matrix Converter (IMC). Two different PWM control techniques such as Carrier Based Pulse Width Modulation Technique and Modified Space Vector Pulse Width Modulation Technique are proposed to analyze the performance of QZSIMC. By changing the shoot through time period, the duty ratio of quasi Z-Source network can be increased which in turn increases the boost factor of both QZSIMC without affecting the efficiency of the converter. A closed-loop control system has also been designed to sustain constant parameters at the output. The proposed QZSIMC for PMG based DDWECS along with two different PWM Control Schemes are to be modeled using MATLAB/SIMULINK environment. To validate the simulation results, a 1 kW, 415 V, 50 Hz experimental setup with an FPGA SPARTAN-6 processor has been developed in the laboratory for QZSIMC and the results are investigated based on the parameters such as output voltage, output current, Switching Stress, Boost Factor, inductor current, capacitor voltage, Total Harmonic Distortion.

Five-phase induction motor drive-A comprehensive review

Modern Electrical Vehicles (EV) and Electric Traction rely heavily on electrical drives. Every day, electric vehicles are being improved and expanded to include commercial vehicles such as passenger vehicles, goods delivery vehicles, and agricultural vehicles. Today, researchers are concentrating on multi-phase electrical drives to improve EV technology. This article provides a comprehensive analysis of the Five-Phase Induction Motor (FPIM) drive. The proposed study investigates the FPIM drive in terms of mathematical modeling and design, the different topologies of a Five-Phase Voltage Source Inverter (FPVSI) (Two-Level, Multi-Level, Matrix), the methodologies utilised to generate the pulse for FPVSI (Carrier-Based Pulse Width Modulation (CBPWM), Space Vector Pulse Width Modulation (SVPWM)), and the control of FPIM. This study evaluates the many strategies available in the literature for controlling the FPIM in order to assist researchers and industrial Research and Development (R&D) engineers in selecting the most suitable tool for their applications.

An ampere‐second‐vector pulse width modulation technique and fault‐tolerant control for CSI11 fed five‐phase permanent magnet synchronous motor with multiple harmonic electromotive forces

AbstractWhen dealing with safety‐critical applications that involve multiphase permanent magnet synchronous motors (PMSMs), the current source inverter (CSI) is a superior choice compared with the voltage source inverter. The conventional technique of pulse width modulation (PWM) presents a challenge for CSI, particularly during faults. The fault‐tolerant control of multiphase PMSMs fed by CSIs has not been well investigated, particularly in situations involving double‐phase open‐circuit faults. Furthermore, fault‐tolerant control becomes more complex when the multiphase PMSM includes harmonic back electromotive forces (EMFs). To deal with these issues, an ampere‐second (AS) vector PWM technique is developed for a five‐phase PMSM powered by CSI11. The modulation ratio of the proposed PWM is identical to that of space vector PWM. The proposed method, however, is easier to implement. A fault‐tolerant control method using AS‐vector is proposed for single‐phase, adjacent double‐phase, and non‐adjacent double‐phase open‐circuit faults. Additionally, a method is developed to suppress the torque ripple that results from harmonic back‐EMFs during fault conditions. Compared without the torque ripple suppression method, during the speed rising, the proposed method can reduce torque ripple to 16.7%, 54.5%, and 37.5%, respectively. The experiments have confirmed the effectiveness of the proposed PWM technique and fault‐tolerant control method.

Improved power sharing in inverter based microgrid using multi-objective optimization

The voltage-source inverter has an important role in electrical power sharing in microgrids, although, it requires a tight control and optimization technique to enhance performance and to improve power sharing. A sudden load change is a common phenomenon which may lead to fluctuations in the terminal voltages and load currents and eventually the system might become unstable. The PI control law represents one of the preferred control algorithms in industry, meanwhile its parameters need to be tuned to ensure its superiority. Two multi-objective optimization algorithms, the Genetic Algorithm, and the Water Cycle Algorithm, are proposed in this article to tune the controller gains. A microgrid consisting of two-parallel inverters is used to investigate the performance of the proposed tuning techniques where the system is analyzed in the dq-frame and the Space Vector Pulse Width Modulation was undertaken as a switching technique. MATLAB/SIMULINK simulations demonstrated the improved performance of the proposed approach.